Liquid fuel burning air heater assembly



Oct. 18, 1955 Filed Aug. 19, 1952 E. A. SALNERS ET AL LIQUID FUEL BURNING AIR HEATER ASSEMBLY 9f a. is

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LIQUID FUEL BURNING AIR HEATER ASSEMBLY Filed Aug. 19. 1952 4 Sheets-Sheet 2 Oct. 18, 1955 E. A. SALNERS ETAL 2,720,876

LIQUID FUEL BURNING AIR HEATER ASSEMBLY Filed Aug. 19, 1952 4 Sheets-Sheet 3 ain/622545 gdwwzd a. Safnms Qfe/zsc/ze/ CZ ezsaz ct. 18, 1955 E. A. SALNERS ET AL $2,876

LIQUID FUEL BURNING AIR HEATER ASSEMBLY Filed Aug. 19. 1952 4 Sheets-Sheet 4 lA/LET THROUGH PLATE 15 T0 HEADER 25? IN V EN TORS.

2,72%,876 LIQUID FUEL BURNING HEATER ASSEMBLY Edward A. Salncrs and Herschel A. Setser, Chicago, and Jerome G. Zahradka, Cicero, Ill., assignors to Motorola, inc, Chicago, 1th, a corporation of Illinois Application August 19, 1952,;Serial No. 305,132 9 Claims. (Cl. 126-110) The present invention relates to air heaters of the type consuming liquid fuel such as gasoline or kerosene; and more particularly to an improved heating mechanism for heating a space of moderate size such as an individual room or an area of a house or factory, or the interior of a vehicle.

The major requirements for heaters of the abovementioned type are that they be inconspicuously small; have compact, simple and relatively inexpensive construction; and be capable of generating ample heat. Liquid fuel burning heaters are known to the art in which a volume of liquid fuel is burned directly at the surface thereof, or is fed by a wick to a combustion chamber. However, such heaters are not generally satisfactory because the burner structure is large in proportion to the heat obtainable therefrom, and they usually require a chimney to create the necessary draft. In another type of known liquid fuel burner, the liquid fuel is atomized by a high pressured air jet prior to its application to the combustion chamber. This produces a combustible spray of fuel in the combustion chamber that may be ignited to effectuate the heating process. The latter arrangement requires a relatively large amount of power to carry out the atomizing process and is practical only in large installations. Yet another type of liquid fuel burner is known in which the fuel is vaporized and mixed with air in a heated conditioning chamber to produce a combustible mixture which is supplied to the combustion chamber in which it is ignited and burned. This arrangement is advantageous since the power requirement is low, its efficiency is big and the necessary equipment is relatively simple, compact and inexpensive. However, although such a heater has been used in automobiles and other vehicles, its use for domestic and household purposes has been rather limited due to the relatively high household heat requirements which necessitates a high rate of fuel vaporization in the conditioning chamber. Such a high rate of fuel vaporization has been considered diliicult to achieve in this type of heater especially since it is desirable to use low volatile fuel such as kerosene in household applications.

Co-pending application Serial No. 52,169 filed October 1, 1948, in the name of Stanley J. Budlane, entitled Liquid Fuel Burning Heater, and assigned to the present assignee, which issued March 30, 1954 as Patent 2,673,558, discloses and claims a heater utilizing the principle of fuel conditioning and vaporizing described above and which is constructed to overcome the above mentioned difficulties and problems so as to be eminently suitable for household purposes. The heater disclosed in the Budlane application achieves a high and stable rate of fuel vaporization even though low volatile fuel is used. The fuel conditioning chamber in the Budlane arrangement is maintained at the optimum vaporization temperature by redirecting the pilot flame, normally used to ignite the main burners, back against the fuel conditioning chamber. Moreover, in order that the optimum temperature will not be exceeded as one or more main 2,720,876 Patented Oct. 18, .1955

burners are brought into operation, the heater is constructed so that heat from the main burner is directed [away from :the fuel conditioning chamber so that that chamberwcontinues to derive its heat solely from the .pilot flame.

The present invention constitutes an improvement over the arrangement disclosed in the aforementioned rBudlane application, and its principal object is to provide an improved liquid fuel consuming heater for small and medium sized domestic and household installations, the heater being'constructed so as to be compact in size, so that eflicient use is made of the various components .comprising theheater, and so that these components may e readily accessible and removable for replacement and servicing.

A further object of the invention is to provide an improved liquid .fuel consuming heater that is highly efficient in operation and yet which has a relatively low power consumption.

Yet another object of the invention is .to provide an improved liquid fuel consuming heater that is relatively simple in its construction and which may be marketed at a relatively low cost.

A further object of the invention is to provide an improved liquid fuel consuming heater in which the various components are mounted, arranged and utilized in ;a new and improved fashion.

The features of the invention which are believed to be new are set forth with particularity in the appended .claims. The invention itself, however, together with further objects and advantages thereof, may best be understood by reference to the accompanying drawings, in which:

Fig. 1 shows the heater of this invention enclosed in a suitable housing;

Fig. 2 is a front view of the heater with the housing removed;

Figs. 3 and 4 are side and top views, respectively, of the heater;

Fig. 5 shows a rear view of the assembly with several components removed to show the duct system; and

Fig. 6 is a side view of the assembly partly in section also with several components removed so as to illustrate the duct system.

The liquid fuel consuming heater of the invention comprises a vertical mounting plate which is adapted to be supported by a wall or the like. A burner assembly is spaced from the front of the mounting plate, the assembly being supported by a combustion air inlet duct communicating with the burner assembly and extending through the vertical mounting plate for providing combustion air for the burner assembly, and also being supported by an exhaust duct communicating with the burner assembly and extending through the mounting plate for removing exhaust gases from the burner assembly. A heat exchanger means is secured to the burner assembly and extends laterally therefrom, and a driving motor-is supported in a vertical axis below the heat exchanger. An air circulating fan is supported by and above the driving motor for circulating air upwardly past the heat exchanger, and a combustion air fan is supported below the motor and also driven by the motor. Finally, a further duct is supported by the mounting plate and supplies combustion air from the combustion air fan to the previously mentioned combustion air inlet duct.

As shown in Fig. 1, the heater is enclosed in a steel cabinet 10 which has a baked enamel finish on its outer surface. Circulating air inlet louvers 11 are formed at each side of the cabinet and at the bottom, and these louvers are preferably equipped with aluminum mesh filters inside the cabinet. A circulating air outlet louver 12 is formed in the top of the cabinet. Circulating air is drawn in through the inlet louvers 11, heated and forced out through the output louver 12 in a manner to be described. The unit also includes a temperature control knob 13 at the top, and also a humidifier cap 14 through which water may be poured into a humidifier water container mounted in the interior of the heater unit.

Referring now to Figs. 2, 3 and 4, the heater unit illustrated therein includes a vertical mounting plate 15 adapted to be supported by a wall or the like. A horizontal shelf 16 having a central orifice or aperture 16a is supported by the mounting plate, and an air circulating fan 17 is disposed in the orifice to direct circulating air upwardly through the orifice. Fan 17 is supported by a vertically disposed motor 18 and is driven by the motor. The motor itself is supported on a mounting bracket 19 which, in turn, is rigidly supported on the top of a cylindrical combustion fan housing 20 by three studs 21a, 21b and 210. Housing 20 contains a combustion air fan 17a which is supported below and driven by motor 18. The bottom of housing 20 is fiat with a central aperture through which fan 17a draws air to be supplied to the burner assembly of the heater. The housing rests on three shock mounts 22a, 22b, 22c which, in turn, are held in respective brackets 23a, 23b, 230. The latter brackets are secured to a cylindrical air header 24, and the header is supported by vertical mounting plate 15 and communicates with a combustion air inlet duct 24a (Figs. 3, 5 and 6) secured to and extending down the back of the mounting plate. Inlet duct 24:: communicates with an air inlet pipe 24b which extends through the wall supporting the heater assembly to the outside atmosphere. Header 24 has an apertured top portion and is flexibly coupled to the aperture in the bottom of housing 20 by means of a flexible coupling 20a comprising a pair of annular members in respective frictional engagement with the apertures in housing 20 and header 24, the annular members having an airtight flexible bellows extending therebetween. Housing 20 is flexibly coupled to a resilient transition piece 25 having a resilient apertured portion 25a (Fig. 3) extending into and frictionally held in an outlet aperture in housing 20. The transition piece is rigidly secured to mounting plate 15 adjacent duct 24a and communicates through the mounting plate with a further duct 36a leading up to the back of the plate to the burner assembly of the heater and supplying combustion air to that assembly in a manner to be described. The housing 20, therefore, provides a floating mounting for motor 18 so that vibrations of the motor are not communicated to the assembly as a whole.

The heater unit includes a heat control 26 which is constructed as a self-contained unit to facilitate its removal for servicing. Control 26 is mounted on plate 15 below shelf 16 and adjacent fan housing 20, and a control rod 27 extends therefrom to knob 13 at the top of the cabinet, the control rod being rotatably supported on plate 15 by a bracket 28. The unit has two functions: the first being to constitute a main switch for the energizing circuits of the heater, and the second being to constitute a control for the energizing circuits of the main burners of the heater to regulate these burners in accordance with manually set ambient temperature levels.

Control unit 26 includes a socket 39 which may be plugged to the 110 volt alternating-current mains, and includes a further socket 80 which receives a plug connecting the unit to the other components of the heater. Sockets 80 and 89 are appropriately connected to the switch contacts of the heat control unit. In this man ner, the control unit may be easily removed merely by pulling the plugs, disengaging control rod 27, and removing the screws mounting the unit on plate 15.

The power supply unit for the heater is indicated generally as 29 and is supported by vertical plate 15 below shelf 16 adjacent the heat control unit 26. The power supply unit includes a transformer 30. The power supply also includes fuses 31, and further includes a relay 33 which, when energized, opens a contact in the energizing circuit to an igniter unit incorporated in the burner assembly of the heater to discontinue the igniter once the burning process has been initiated. The power supply also includes a terminal block 32 having a series of terminal contacts to which connection is made to complete the electrical control circuit. A socket 58 is included in the unit and connected to various components thereof so that the unit, like heat control 26, may be readily disassociated from the heater circuit for easy removal.

A safety switch 34 is included in the power supply unit which serves to discontinue the fuel supply to the igniter should the ignition process fail.

vAn open topped humidifier container 35 is secured to vertical mounting plate 15 above the shelf 16 and in communication with plug 14 of Fig. 1 so that water may be added to the humidifier from time to time.

A rectangular shaped combustion air inlet duct 36 (Figs. 3, 5 and 6) extends through and is supported by plate 15, and this duct communicates with transition piece 25 by means of the duct 36a secured to and extending down the back of plate 15 adjacent duct 24a. A circular exhaust duct 37 also extends through and is supported by plate 15, and the exhaust duct communicates with an exhaust pipe 37a extending coaxially within air inlet pipe 24b through the supporting wall to the outside atmosphere.

A fuel metering base 59 is supported at the top of air duct 36 and supports a series of solenoid operated fuel metering valves 3841 which, with the base, constitute a fuel metering unit. A fuel pump 42 is supported on a bracket 43 extending from the back of base 59, and fuel such as kerosene, gasoline or the like is supplied to the pump by a fuel line 44 extending thereto from a filter unit 45, the latter unit being supported by the fuel line. The fuel is supplied to the filter unit by an inlet fuel line 46 extending from the back of the filter and through mounting plate 15 to a suitable fuel tank. A surge chamber 47 is coupled to filter 45 by a line 48 and functions in wellknown fashion. Fuel from the pump is supplied by a line 50 to a pressure regulator 49, and fuel from the pressure regulator is supplied by a line 51 to the interior of base 59.

The ducts 36 and 37 extend through and support a vertical plate 52 which, in turn, supports a burner assembly 53. A heat exchanger 54 is mounted on the burner assembly and extends laterally from each side thereof. The heat exchanger comprises a re-entrant passage at each side of the burner assembly one end of which communicates with a combustion chamber within the burner assembly and the other end with exhaust duct 37. An electrically operated igniter unit 55 is supported by the burner assembly and is used to initiate the heating process therein. The electrical connections to the fuel pump and to the metering valves in the fuel metering unit are conveniently terminated in a plug which engages a socket (Fig. 4) so that the fuel pump, pressure regulator and fuel metering unit (which are constructed as a self-contained unit) may be easily removed from the heater.

The arrangement of the fuel metering unit, fuel pump, burner assembly and heat exchanger may be similar to that disclosed in co-pending applications Serial No. 305,176, filed August 19, 1952, in the name of Cado et al.; and Serial No. 305,120, filed August 19, 1952, in the name of Zahradka, both assigned to the present assignee, and a detailed description herein is deemed unnecessary. Briefly, burner assembly 53 comprises a vaporizing block of heat conducting material with a series of horizontal fuel vaporizing or conditioning passages extending therethrough. Two of the passages constitute main burner passages and terminate in main burner ports at the front of the block. The main burner ports communicate tangentially with an open ended cylindrical combustion chamber extending across the front of the block which, in turn, communicates at each end with the aforementioned passages in heat exchanger 54. The combustion products from the combustion chamber are directed around the heat exchanger and back to ,a casing enclosingthe combustion block and thence out through exhaust duct 37. The vaporizing block has a further passage extending horizontally therethrough in heat conducting relationship with the main burner passages and terminating at the front of the block in a pilot burner port in igniting relationship with the main burner port. The block has a still further passage extending ,therethrough in heat conducting relationship with the pilot burner passage, and which directs a flame from igniter unit 55, the flame being used to heat the pilot burner passage and ignite the pilot burner.

Pressure regulator 49 supplies fuel to the interior of base 59 and solenoid valves 38-41 are electrically operated selectively to supply fuel to the igniter unit 53 and to the pilot and main burner passages in the vaporizing block. Air duct 36 communicates with the igniter unit and the passages in the vaporizing block and combustion air is supplied to the igniter and to the passages by fan 17a, the fan drawing air through air inlet pipe 24b, down duct 24a and through header 24, and forcing air through transition piece 25 and up through the aforementioned duct 36a communicating with duct 36.

A pair of thermal-responsive electric switches 56 and 57 are screwed into the bottom of the vaporizer block of the burner assembly 53 for controlling the energization of the fuel-metering unit and of fan motor 18. These switches may be similar to the switch disclosed and claimed in co-pending application Serial No. 108,283, filed in the name of Michael J. LaRocco, August 3, 1949, entitled Thermal Switch and assigned to the present assignee and which has now issued as Patent No. 2,641,668, on June 9, 1953 Vertical mounting plate is secured to the supporting wall by a stud 200 (Fig. 3); and by a leveling arrangement consisting of a bracket 201 secured to the wall, a bracket 2tl2 welded to plate 15, and a vertical stud 203. By adjustment of stud 203 the heater may be accurately positioned on the supporting wall.

The invention provides, therefore, a new and improved heater unit in which the various components are constructed and positioned to achieve maximum efficiency and economy in a minimum of space. Moreover, the various components of the heater are arranged to -be readily accessible so that they may be quickly and convenientlyremoved for servicing purposes. In addition, the heater of this invention is constructed to be fully automatic and to provide constant heat at any desired temperature.

While a particular embodiment of the invention has been shown and described, modifications may be made, and it is intended in the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.

We claim:

1. A liquid fuel-consuming heater including in combination; a vertical mounting plate adapted to be supported by a wall or the like; a burner assembly spaced from the front of said vertical mounting plate; an air duct communicating with said burner assembly and extending through said vertical mounting plate for pro viding air for combustion to said burner assembly; an exhaust duct communicating with said burner assembly and extending through said vertical mounting plate for removing exhaust gases from said burner assembly; heat exchanger means secured to said burner assembly and extending laterally therefrom; a driving motor, including a drive shaft, and supported below said heat exchanger means with the axis of said shaft in a vertical position; an air-circulating fan supported on said drive shaft above said motor and driven by said driving motor for circulating air upwardly past said heat exchanger means; a combustion-air fan supported on said drive shaft below said motor and driven by said driving motor; and a further duct coupling said combustion air fan with said air duct for forcing combustion air through said burner assembly.

2. A liquid fuel-consuming heater including in combination; a vertical mounting plate adapted to be supported by a wall or the like; a burner assembly spaced from the front of said vertical mounting plate; an air duct for supplying air for combustion to said burner assembly, said air duct extending through and supported by said mounting plate and communicating with andsupporting said burner assembly; an exhaust duct extending through and supported by said mounting plate for re movingexhaust gases from said burner assembly; heat exchanger means secured to said burner assembly and extending laterally therefrom; a driving motor, including a drive shaft, and supported below said heat exchanger means With the axis of said shaft in a vertical position; an air-circulating fan supported on said drive shaft above said motor and driven thereby for circulating air upwardly past said heat exchanger means; a combustion-air fan supported on said drive shaft below said motor and driven thereby; and a further duct supported at the back of said vertical mounting plate coupling said combustion-air fan to said air duct for supplying combustion air to said air duct and through said burner assembly to said exhaust duct.

3. A liquid fuel-consuming heater including in com bination; a vertical mounting plate adapted to be supported by a wall or the like; a burner assembly spaced from the front of said vertical mounting plate; an air duct communicating with said burner assembly and extending through said vertical mounting plate for providing air for combustion to said burner assembly; an exhaust duct communicating with said burner assembly and extending through said vertical mounting plate for removing exhaust gases from said burner assembly; heat exchanger means secured to said burner assembly and extending laterally therefrom; a horizontal plate supported at the front of said vertical mounting plate below said heat exchanger means and having a central orifice therein; a driving motor, including a drive shaft, and supported below said horizontal plate with the axis of said drive shaft in a vertical position; an air-circulating fan supported on said drive shaft above said driving motor in alignment with said orifice and driven by said driving motor for circulating air upwardly past said heat exchanger means; a combustion-air fan supportedon said drive shaft below said motor and driven by said driving motor, and a further duct coupling said combustion-air fan with said air duct for forcing combustion-air through said burner assembly.

4. A liquid fuel-consuming heater including in combination; a vertical mounting plate adapted to be supported by a wall or the like; a burner assembly spaced from the front of said vertical mounting plate; an air duct communicating with said burner assembly and extending through said vertical mounting plate for providing air for combustion to said burner assembly; an exhaust duct communicating with said burner assembly and extending through said vertical mounting plate for removing exhaust gases from said burner assembly; heat exchanger means secured to said burner assembly and extending laterally therefrom; an air header secured to the front of said mounting plate and extending outwardly therefrom below said heat exchanger means, said header having an inlet opening adjacent said mounting plate and further having an outlet opening formed therein, a further duct communicating with an. air inlet and supported by and extending down the back of said mounting plate, said further duct communicating with said inlet opening in said header; a fan housing having an inlet opening and an outlet opening, resilient means for supporting said fan housing on said header unit; a driving motor, including a drive shaft, and rigidly supported on said housing below said heat exchanger means with said drive shaft in a vertical position; an air-circulating fan supported on said drive shaft above said motor and driven by said driving motor for circulating air upwardly past said heat exchanger means; a combustionair fan supported on said drive shaft below said motor within said housing and driven by said motor; air-tight flexible means for coupling said outlet opening of said header unit to the inlet opening of said housing; a further duct extending upwardly to said air duct for supplying combustion-air to said air duct, and airtight resilient means for flexibly coupling said further duct to the outlet opening of said housing.

5. In a heater unit, a vertical mounting plate adapted to be supported by a wall or the like; an air duct supported by said plate and extending to the bottom of said plate; a header unit secured to the front of said plate at the bottom thereof and having an inlet opening and an outlet opening extending into the interior of said header, said inlet opening of said header communicating with said air duct; a fan housing having an inlet opening and an outlet opening, means for flexibly supporting said fan housing on said header unit; a driving motor, including a drive shaft, and rigidly supported on said housing with the axis of said drive shaft in a vertical'position; a fan supported on said drive shaft below said motor within said housing and driven by said motor; air-tight flexible means for coupling said outlet opening of said header to said inlet opening of said housing; a further duct supported by said plate and extending upwardly from the bottom thereof; and flexible means for coupling said further duct to the outlet opening of said housing.

6. In a heater unit, a vertical mounting plate adapted to be supported by a wall or the like; an air duct supported by said plate and extending to the bottom of said plate; a cylindrical header unit secured to the front of said plate at the bottom thereof, said header extending outwardly from said plate and having a top with an outlet opening therein and a side with an inlet opening therein, said inlet opening communicating with said air duct; a cylindrical fan housing having an inlet opening at the bottom thereof and having an outlet opening, means for flexibly supporting said fan housing on said header unit with said inlet opening in the bottom of said fan housing disposed over said outlet opening in said header; a driving motor, including a drive shaft, and rigidly supported on said housing with the axis of said drive shaft in a vertical position; a fan supported on said drive shaft below said motor within said housing and driven by said motor; air-tight flexible means for coupling said outlet opening of said header to said inlet opening of said housing; a further duct supported by said plate and extending upwardly from the bottom thereof; and flexible means for coupling said further duct to said outlet opening of said housing.

7. In a heater unit, a vertical mounting plate adapted to be supported by a wall or the like; an air duct supported by said plate and extending to the bottom of said plate; a cylindrical header unit secured to the front of said plate at the bottom thereof, said header unit extending outwardly from said plate and having an apertured top portion and also having a side portion with an aperture therein communicating with said air duct; a cylindrical fan housing having an apertured bottom portion and an apertured side portion; flexible bracket means for supporting said fan housing in a horizontal position on said header unit but spaced therefrom; a driving motor,

including a drive shaft, and rigidly supported on said fan housing with the axis of said shaft in a vertical portion; a fan supported by said drive shaft below said motor within said housing and driven thereby; air-tight flexible means extending between said apertured top of said header unit and said apertured bottom of said fan housing for coupling said header to the interior of said fan housing; a further duct supported by said plate and extending upwardly from the bottom thereof; and flexible means for coupling said further duct to the interior of said fan housing through said apertured side portion of said housing.

8. An air supply source fora combustion heater or the like including in combination; a cylindrical air header unit having an inlet aperture therein and further having an apertured top portion; a cylindrical fan housing having an outlet aperture therein and further having an apertured bottom portion; flexible bracket means for supporting said housing in a horizontal position on said header unit but spaced therefrom; a driving motor, including a drive shaft, and rigidly supported on said fan housing with the axis of said shaft in a vertical position; a fan supported by said drive shaft below said motor within said housing and driven thereby; and air-tight flexible means extending between said apertured top of said header and said apertured bottom of said housing for coupling said header to the interior of said housing.

9. An air supply source for a combustion heater or the like including in combination; a cylindrical air header unit having an inlet aperture therein and further having an apertured top portion; a cylindrical fan housing having an outlet aperture therein and further having an apertured bottom portion; flexible bracket means for supporting said housing on said header unit with said housing over said header but spaced therefrom; a driving motor, including a drive shaft, and rigidly supported on said fan housing with said drive shaft in a vertical position; a fan supported by said drive shaft below said motor within said housing and driven thereby; and air-tight flexible means extending between said apertured top of said header and said apertured bottom of said housing for coupling said header to the interior of said housing, said last-named means comprising a first annular portion in frictional engagement with said apertured top, a second annular portion in frictional engagement with said apertured bottom, and a bellows of air-tight flexible material interconnecting said first and second annular portions.

References Cited in the file of this patent UNITED STATES PATENTS 1,973,187 Van Sciver Sept. 11, 1934 2,322,924 Daiger June 29, 1943 2,375,920 Hewitt May 15, 1945 2,517,398 McCollum Aug. 1, 1950 2,588,349 Dusek et al Mar. 11, 1952 2,588,352 Budlane Mar. 11, 1952 2,615,617 Lattner Oct. 18, 1952 2,665,841 Smith Jan. 12, 1954 

